Endangered Cacti in Arizona

Science Center Objects

Arizona is the home to at least 10 cacti that are listed as endangered, threatened, or under conservation agreement. Land use and management activities that occur on federal, and to some extent state, lands on which the cacti occur require consultation among the U.S. Fish and Wildlife Service (USFWS), the agency managing the land on which the cacti is growing, and the party proposing an activity on that land, if not the managing agency. USGS scientists are often asked to provide scientific input to the USFWS and/or the managing agency to help guide their consultation on proposed actions or to provide up-to-date data on the health of the cactus populations. SBSC scientists are conducting studies on two endangered cacti: the Arizona hedgehog cactus and the Pima pineapple cactus.

Background & Importance

The Arizona hedgehog cactus grows in rugged shrubland country in central Arizona where the lower deserts transition to higher plateaus. Within its habitat are current mines and plans for extensive development of new mining operations. The USFWS has sought USGS help in evaluating the sufficiency of existing monitoring data toward providing a comprehensive view of the status and health of the Arizona hedgehog cactus.

The Pima pineapple cactus occurs in desert grasslands and transitional shrublands mainly in south-central Arizona. Within the cactus’ habitat native grasslands have been invaded by non-native grasslands and range expansion of mesquite. Prescribed fire is a management tool that ranchers and wildlife refuge managers want to use to manage rangeland health. The USFWS asked the USGS to evaluate the survival of the Pima pineapple cactus after fire and when protective clearing of vegetation was applied around each cactus before the fire.  

Close-up of a small Pima pineapple cactus in coarse-textured soil in the desert.

Pima pineapple cactus and vegetative offshoot, commonly called a pup, in the Altar Valley of south-central Arizona (November 2014). (Credit: Chris Jarchow, USGS. Public domain.)

Semi-desert grassland of the Altar Valley in south-central Arizona dominated by nonnative lovegrass.

Semi-desert grasslands of the Altar Valley in south-central Arizona, which is the habitat of the Pima pineapple cactus. Nonnative lovegrass dominates and small mesquite trees have expanded into the grassland, and the Baboquivari Mountains are in the background (November 2014). (Credit: Chris Jarchow, USGS. Public domain.)